#!/bin/bash
#
# apt-fast v1.8
# Use this just like aptitude or apt-get for faster package downloading.
#
# Copyright: 2008-2012 Matt Parnell, http://www.mattparnell.com
# Improvements, maintenance, revisions - 2012 Dominique Lasserre
#
# You may distribute this file under the terms of the GNU General
# Public License as published by the Free Software Foundation; either
# version 3 of the License, or (at your option) any later version.
#
[ -n "$DEBUG" ] && set -xv

# Print colored messages.
# Usage: msg "message text" "message type" "optional: err"
# Message types are 'normal', 'hint' or 'warning'. Warnings and messages with a
# third argument are piped to stderr.
msg(){
  case "$2" in
    normal) beginColor="$cGreen";;
    hint) beginColor="$cBlue";;
    warning) beginColor="$cRed";;
  esac

  if [ -z "$3" ] && [ "$2" != "warning" ]; then
    echo -e "${aptfast_prefix} ${beginColor}$1${endColor}";
  else
    echo -e "${aptfast_prefix} ${beginColor}$1${endColor}"; >&2
  fi
}

# Search for known options and decide if root privileges are needed.
root=1  # default value: we need root privileges
option=
for arguments in $@; do
  if [ "$arguments" == "upgrade" ] ||
      [ "$arguments" == "install" ] ||
      [ "$arguments" == "dist-upgrade" ] ||
      [ "$arguments" == "build-dep" ]; then
    option="install"
    break
  elif [ "$arguments" == "clean" ] ||
      [ "$arguments" == "autoclean" ]; then
    option="clean"
    break
  elif [ "$arguments" == "download" ]; then
    option="download"
    root=0
    break
  elif [ "$arguments" == "source" ]; then
    option="source"
    root=0
    break
  elif [ "$arguments" == "changelog" ]; then
    root=0
    break
  fi
done

# To handle priority of options correctly (environment over config file vars)
# we need to preserve all interesting env variables. As this wouldn't be
# difficult enough we have to preserve complete env vars (especially if value
# ist set (even empty) or not) when changing context (sudo)...
# Set a 'random' string to all unset variables.
TMP_RANDOM="13979853562951413"
TMP_LCK_FILE="${LCK_FILE-${TMP_RANDOM}}"
TMP_DOWNLOADBEFORE="${DOWNLOADBEFORE-${TMP_RANDOM}}"
TMP__APTMGR="${_APTMGR-${TMP_RANDOM}}"
TMP_APTCACHE="${APTCACHE-${TMP_RANDOM}}"
TMP_DLDIR="${DLDIR-${TMP_RANDOM}}"
TMP_DLLIST="${DLLIST-${TMP_RANDOM}}"
TMP_LISTDIR="${LISTDIR-${TMP_RANDOM}}"
TMP__MAXNUM="${MAXNUM-${TMP_RANDOM}}"
TMP__MAXCONPERSRV="${MAXCONPERSRV-${TMP_RANDOM}}"
TMP__SPLITCON="${SPLITCON-${TMP_RANDOM}}"
TMP__MINSPLITSZ=${MINSPLITSZ-${TMP_RANDOM}}
TMP__PIECEALGO=${PIECEALGO-${TMP_RANDOM}}
TMP_aptfast_prefix="${aptfast_prefix-${TMP_RANDOM}}"
TMP_APT_FAST_TIMEOUT="${APT_FAST_TIMEOUT-${TMP_RANDOM}}"

# Check for proper privileges.
# Call explicitly with environment variables to get them into root conext.
if [ "$root" = 1 -a "$UID" != 0 ]; then
  exec sudo DEBUG="$DEBUG" \
            LCK_FILE="$TMP_LCK_FILE" \
            DOWNLOADBEFORE="$TMP_DOWNLOADBEFORE" \
            _APTMGR="$TMP__APTMGR" \
            APTCACHE="$TMP_APTCACHE" \
            DLDIR="$TMP_DLDIR" \
            DLLIST="$TMP_DLLIST" \
            LISTDIR="$TMP_LISTDIR" \
            _MAXNUM="$TMP__MAXNUM" \
            _MAXCONPERSRV="$TMP__MAXCONPERSRV" \
            _SPLITCON="$TMP__SPLITCON" \
            _MINSPLITSZ="$TMP__MINSPLITSZ" \
            _PIECEALGO="$TMP__PIECEALGO" \
            aptfast_prefix="$TMP_aptfast_prefix" \
            APT_FAST_TIMEOUT="$TMP_APT_FAST_TIMEOUT" "$0" "$@"
fi


# Define lockfile.
# Use /tmp as directory because everybody (not only root) has to have write
# permissions.
# We need lock for non-root commands too, because we only have one download
# list file.
LCK_FILE="/tmp/apt-fast"
LCK_FD=99

# Set default package manager, APT cache, temporary download dir,
# temporary download list file, and maximal parallel downloads
_APTMGR=apt-get
eval $(apt-config shell APTCACHE Dir::Cache::archives/d)
# Check if APT config option Dir::Cache::archives::apt-fast-partial is set.
eval $(apt-config shell apt_fast_partial Dir::Cache::archives::apt-fast-partial/d)
if [ -z "$apt_fast_partial" ]; then
  eval $(apt-config -o Dir::Cache::archives::apt-fast-partial=apt-fast shell DLDIR Dir::Cache::archives::apt-fast-partial/d)
else
  eval $(apt-config shell DLDIR Dir::Cache::archives::apt-fast-partial/d)
fi
# Currently not needed.
eval $(apt-config shell LISTDIR Dir::State::lists/d)
DLLIST="/tmp/apt-fast.list"
_MAXNUM=8
_MAXCONPERSRV=10
_SPLITCON=8
_MINSPLITSZ="1M"
_PIECEALGO="default"

# Prefix in front of apt-fast output:
aptfast_prefix=

# Set color variables.
cGreen='\e[0;32m'
cRed='\e[0;31m'
cBlue='\e[0;34m'
endColor='\e[0m'

# Set timout value for apt-fast download confirmation dialog.
# Value is in seconds.
APT_FAST_TIMEOUT=60

# Download command.
_DOWNLOADER='aria2c -c -j ${_MAXNUM} -x ${_MAXCONPERSRV} -s ${_SPLITCON} -i ${DLLIST} --min-split-size=${_MINSPLITSZ} --stream-piece-selector=${_PIECEALGO} --connect-timeout=600 --timeout=600 -m0'

# Load config file.
CONFFILE="/etc/apt-fast.conf"
if [ -e "$CONFFILE" ]; then
    source "$CONFFILE"
fi

# Now overwrite with preserved values if values were set before (compare with
# 'random' string).
[ "$TMP_LCK_FILE" = "$TMP_RANDOM" ] || LCK_FILE="$TMP_LCK_FILE"
[ "$TMP_DOWNLOADBEFORE" = "$TMP_RANDOM" ] || DOWNLOADBEFORE="$TMP_DOWNLOADBEFORE"
[ "$TMP__APTMGR" = "$TMP_RANDOM" ] || _APTMGR="$TMP__APTMGR"
[ "$TMP_APTCACHE" = "$TMP_RANDOM" ] || APTCACHE="$TMP_APTCACHE"
[ "$TMP_DLDIR" = "$TMP_RANDOM" ] || DLDIR="$TMP_DLDIR"
[ "$TMP_DLLIST" = "$TMP_RANDOM" ] || DLLIST="$TMP_DLLIST"
[ "$TMP_LISTDIR" = "$TMP_RANDOM" ] || LISTDIR="$TMP_LISTDIR"
[ "$TMP__MAXNUM" = "$TMP_RANDOM" ] || _MAXNUM="$TMP__MAXNUM"
[ "$TMP__MAXCONPERSRV" = "$TMP_RANDOM" ] || _MAXCONPERSRV="$TMP__MAXCONPERSRV"
[ "$TMP__SPLITCON" = "$TMP_RANDOM" ] || _SPLITCON="$TMP__SPLITCON"
[ "$TMP__MINSPLITSZ" = "$TMP_RANDOM" ] || _MINSPLITSZ="$TMP__MINSPLITSZ"
[ "$TMP__PIECEALGO" = "$TMP_RANDOM" ] || _PIECEALGO="$TMP__PIECEALGO"
[ "$TMP_aptfast_prefix" = "$TMP_RANDOM" ] || aptfast_prefix="$TMP_aptfast_prefix"
[ "$TMP_APT_FAST_TIMEOUT" = "$TMP_RANDOM" ] || APT_FAST_TIMEOUT="$TMP_APT_FAST_TIMEOUT"


# Disable colors if not executed in terminal.
if [ ! -t 1 ]; then
  cGreen=
  cRed=
  cBlue=
  endColor=
  #FIXME: Time not updated.
  [ -z "$aptfast_prefix" ] && aptfast_prefix="[apt-fast $(date +"%T")]"
fi


msg_already_running()
{
  msg "apt-fast already running!" "warning"
  msg "Verify that all apt-fast processes are finished then remove $LCK_FILE.lock and try again." "hint"
}

# Check if a lock file exists.
if [ -f "$LCK_FILE.lock" ]; then
  msg_already_running
  exit 1
fi


# create the lock file and lock it, die on failure
_create_lock()
{
    eval "exec $LCK_FD>\"$LCK_FILE.lock\""

    trap "_remove_lock; exit" EXIT
    trap "_remove_lock; exit 1;" INT KILL TERM

    flock -n $LCK_FD || { msg_already_running; exit 1; }
}

# unlock and remove the lock file
_remove_lock()
{
    flock -u "$LCK_FD" 2>/dev/null
    rm -f "$LCK_FILE.lock"
}

# decode url string
# translates %xx but must not convert '+' in spaces
urldecode()
{
    printf '%b' "${1//%/\\x}"
}

# Check if mirrors are available. And if so add all mirrors to download list.
get_mirrors(){
  # Check all mirror lists.
  for mirrorstr in ${MIRRORS[@]}; do
    # Build mirrors array from comma separated string.
    mirrors=( $(echo "$mirrorstr" | sed "s/\([^,]\+\)\s*,\s*/\1 /g") )
    # This does not the \s*,\s* trick, so we use sed instead to make it more
    # robust.
    #mirrors=( ${mirrorstr//,/ } )
    # Check for all mirrors if URI of $1 is from mirror. If so add all other
    # mirrors to (resmirror) list and break all loops.
    for mirror in ${mirrors[@]}; do
      # Real expension.
      if [[ "$1" == "$mirror"*  ]]; then
        filepath=${1#${mirror}}
        # Build list for aria download list.
        list="${mirrors[@]}"
        echo -e "${list// /${filepath}\\t}$filepath\n"
        return 0
      fi
    done
  done
  # No other mirrors found.
  echo "$1"
}

# Get the package URLs.
get_uris(){
  # Add header to overwrite file.
  echo "# apt-fast mirror list: $(date)" > "$DLLIST"
  #NOTE: aptitude doesn't have this functionality, so we use apt-get to get
  #      package URIs.
  apt-get -y --print-uris "$@" | egrep "^'(http(s|)|(s|)ftp)://" | \
  while read pkg_uri_info
  do
    ## --print-uris format is:
    # 'fileurl' filename filesize checksum_hint:filechecksum
    uri=$(echo "$pkg_uri_info" | cut -d' ' -f1 | tr -d "'")
    filename=$(echo "$pkg_uri_info" | cut -d' ' -f2)
    filesize=$(echo "$pkg_uri_info" | cut -d' ' -f3)
    checksum=$(echo "$pkg_uri_info" | cut -d' ' -f4 | cut -d':' -f2)
    ## whole uri comes encoded (urlencoded). Filename must NOT be decoded because
    # plain aptitude do not decode it when download and install it. Therefore, we
    # will have ugly named packages at /var/cache/apt/archives but is the standard
    # behavior.
    # But package version must be decoded, otherways package=version calls will
    # not work.

    ## Aria only supports md5 and sha1. If --print-uris return other than
    # MD5, we need to replace it (by now behavior is return strongest).
    # Using apt-cache show package=version to ensure recover single and
    # correct package version.
    # Warning: assuming that package naming uses '_' as field separator.
    # Therefore, this code expects package-name_version_arch.deb Otherways
    # below code will fail resoundingly
    if echo "$pkg_uri_info" | grep -q -v 'MD5Sum'
    then
      pkg_name=$(echo "$filename" | cut -d'_' -f1)
      pkg_version=$(echo "$filename" | cut -d'_' -f2)
      pkg_version=$(urldecode $pkg_version)
      patch_md5=$(apt-cache show $pkg_name=$pkg_version | grep MD5sum | head -n 1)
      checksum=$(echo $patch_md5 | cut -d' ' -f2)
    fi

    echo "$(get_mirrors "$uri")" >> "$DLLIST"
    #echo " dir=$DLDIR" >> "$DLLIST"
    echo " checksum=md5=$checksum" >> "$DLLIST"
    echo " out=$filename" >> "$DLLIST"
  done

  #cat "$DLLIST"
  #LCK_RM
  #exit
}

# Create and insert a PID number to lockfile.
_create_lock

# Make sure aria2c (in general first parameter from _DOWNLOADER) is available.
CMD="$(echo "$_DOWNLOADER" | sed 's/^\s*\([^ ]\+\).*$/\1/')"
if [ ! $(command -v "$CMD") ]; then
  msg "Command not found: $CMD" "normal" "err"
  msg "You must configure $CONFFILE to use aria2c or another supported download manager" "normal" "err"
  exit 1
fi

# Make sure package manager is available.
if [ ! $(command -v "$_APTMGR") ]; then
  msg "\`$_APTMGR\` command not available." "warning"
  msg "You must configure $CONFFILE to use either apt-get or aptitude." "normal" "err"
  exit 1
fi


# Run actions.
if [ "$option" == "install" ]; then
  msg "\n Working... this may take a while." "normal"

  get_uris "$@"

  # Check if "assume yes" switch is enabled and if yes enable $DOWNLOADBEFORE.
  #TODO: Get real value over APT items APT::Get::Assume-Yes and
  #      APT::Get::Assume-No .
  #FIXME: Composed short options e.g. "-yV" are not recognised - we should use
  #      getopts for proper option passing.
  for option in $@; do
    if [ "$option" == "-y" ] ||
        [ "$option" == "--yes" ] ||
        [ "$option" == "--assume-yes" ]; then
      DOWNLOADBEFORE=true
    elif [ "$option" == "--assume-no" ]; then
      DOWNLOADBEFORE=
    fi
  done

  # Test /tmp/apt-fast.list file exists AND not zero bytes.
  # Then download all files from the list.
  if [ $(cat "$DLLIST" | wc -l) -gt 0 ] && [ ! "$DOWNLOADBEFORE" ]; then
    cat "$DLLIST"

    echo -ne "${cRed} If you want to download the packages on your system press Y else n to abort. [Y/n]:  ${endColor}"

    while ((!updsys)); do
      read -sn1 -t "$APT_FAST_TIMEOUT" answer || { msg "\n Timed out." "warning"; exit 1; }
      case "$answer" in
        [JjYy])    result=1; updsys=1 ;;
        [Nn])      result=0; updsys=1 ;;
        "")        result=1; updsys=1 ;;
        *)         updsys=0 ;;
      esac
    done
  else
    result=1
  fi

  echo

  # Continue if answer was right or DOWNLOADBEFORE is enabled.
  if ((result)); then
    if [ -s "$DLLIST" ]; then
      # Test if apt-fast directory is present where we put packages.
      if [ ! -d "$DLDIR" ]; then
        mkdir -p -- "$DLDIR"
      fi

      cd "$DLDIR" &>/dev/null || exit 1

      eval "${_DOWNLOADER}" # execute downloadhelper command
      if [ $(find "$DLDIR" -printf . | wc -c) -gt 1 ]; then
        # Move all packages to the apt install directory by force to ensure
        # already existing debs which may be incomplete are replaced
        find -type f -name "*.deb" -execdir mv -ft "$APTCACHE" {} \+
      fi
      cd - &>/dev/null
    fi
  else
    exit 1
  fi

  "${_APTMGR}" "$@"


elif [ "$option" == "clean" ]; then
  "${_APTMGR}" "$@" && {
    find "$DLDIR" -maxdepth 1 -type f -delete
    [ -f "$DLLIST" ] && rm -f -- "$DLLIST"*
  }

elif [ "$option" == "download" ]; then
  get_uris "$@"
  eval "${_DOWNLOADER}"

elif [ "$option" == "source" ]; then
  msg "\n Working... this may take a while.\n" "normal"
  get_uris "$@"
  eval "${_DOWNLOADER}"
  # We use APT manager here to provide more verbose output. This method is
  # slightly slower then extractiong packages manually after download but also
  # more hardened (e.g. some options like --compile are available).
  "${_APTMGR}" "$@"
  # Uncomment following snippet to extract source directly and comment
  # both lines before.
  #while read srcfile; do
  #  # extract only .dsc files
  #  echo "$srcfile" | grep -q '\.dsc$' || continue
  #  dpkg-source -x "$(basename "$srcfile")"
  #done < "$DLLIST"

# Execute package manager directly if unknown options are passed.
else
  "${_APTMGR}" "$@"

fi


# After error or all done remove our lockfile
